This data set is one component of a digital terrain model (DTM) for the SWFWMD Polk
District. This record includes information about the LiDAR data for the following
SWFWMD tracts: Hampton, Judy, Lake Wales, Peace River (North) and Polk Remainder.
All of these tracts are located in Polk County. Please see the Bounding Coordinates
for each tract for the location within Polk County. Information that is specific to
each tract has been maintained. HAMPTON TRACT This data set is one component of a
digital terrain model (DTM) for Hampton Tract, Polk County, Florida encompassing approximately
43 square miles. This dataset is comprised of 48 LiDAR files, based on the DISTRICT
5,000' by 5,000' sheet index system (17951-17958, 18114-18121, 18363-18370, 18526-18533,
18259-18266 and 18594-18601) in the LAS file format. The raw data was collected at
an average ground sample distance of 1-meter. Other components of the DTM include:
3-D breaklines along hydrographic features in the Shape file format; lake/pond polygons
(in 3D) in the shape file format; obscured area polygons (in 2D) in the Shape file
format; and hard/soft breaklines (in 3D) in the Shape file format. Date of Collection:
20060125 Bounding Coordinates of tract: West Bounding Coordinate: -82.035984 East
Bounding Coordinate: -81.903345 North Bounding Coordinate: 28.328847 South Bounding
Coordinate: 28.238391 JUDY TRACT This data set is one component of a digital terrain
model (DTM) for Judy Tract, Polk County, Florida encompassing approximately 12.6 square
miles. This dataset is comprised of 14 LiDAR files, based on the DISTRICT 5,000' by
5,000' sheet index system (17632-17636, 17795-17799, and 17959-17962) in the LAS file
format. The raw data was collected at an average ground sample distance of 1-meter.
Other components of the DTM include a personal geodatabase containing: obscured vegetation
polygons; road overpass polygons; road breaklines; soft feature breaklines; water
body polygons; coastal shorelines; 1-foot contours; hydrographic feature breaklines,
and island polygons in accordance with the SWFWMD 2006 Topographic Database Design.
Date of Collection: 20060125 Bounding Coordinates of tract: West Bounding Coordinate:
-81.925929 East Bounding Coordinate: -81.848175 North Bounding Coordinate: 28.350110
South Bounding Coordinate: 28.308789 LAKE WALES This data set is one component of
a digital terrain model (DTM) for Lake Wales, Polk County, Florida encompassing approximately
10.75 square miles. This dataset is comprised of 12 LiDAR files, based on the DISTRICT
5,000' by 5,000' sheet index system (22365-22367, 22528-22530, 22691-22693 and 22854-22856)
in the LAS file format. The raw data was collected at an average ground sample distance
of 1-meter. Other components of the DTM include: 3-D breaklines along hydrographic
features in the Shape file format; lake/pond polygons (in 3D) in the shape file format;
obscured area polygons (in 2D) in the Shape file format; and hard/soft breaklines
(in 3D) in the Shape file format. Date of Collection: 20060125 Bounding Coordinates
of tract: West Bounding Coordinate: -81.543294 East Bounding Coordinate: -81.509932
North Bounding Coordinate: 27.916603 South Bounding Coordinate: 27.868213 PEACE RIVER
(NORTH) This data set is one component of a digital terrain model (DTM) for Peace
River North (P692), Polk County, Florida encompassing approximately 1,149 square miles.
This dataset is comprised of 1,281 LiDAR files, based on the DISTRICT 5,000' by 5,000'
sheet index system in the LAS file format. The raw data was collected at an average
ground sample distance of 1-meter. Other components of the DTM include: 3-D breaklines
along hydrographic features in the Shape file format; lake/pond polygons (in 3D) in
the shape file format; obscured area polygons (in 2D) in the Shape file format; and
hard/soft breaklines (in 3D) in the Shape file format. Date of Collection: 20060227
Bounding Coordinates of tract: West Bounding Coordinate: -82.035984 East Bounding
Coordinate: -81.903345 North Bounding Coordinate: 28.328847 South Bounding Coordinate:
28.238391 POLK DISTRICT REMAINDER This dataset is one component of a digital terrain
model (DTM) for the Southwest Florida Water Management District's FY2007 Remainder
Polk District LiDAR Mapping Project and Polk District Contours Project (L672) encompassing
approximately 428 square miles in Polk County, Florida. This dataset is comprised
of 478 LiDAR files, based on the FL Statewide 5,000' by 5,000' sheet index system
in the LAS version 1.1 file format. LiDAR acquisition dates were January 27, January
30 through February 20, 2005. The raw data was collected at an average ground sample
distance of 2.1 feet. Other components of the DTM include a personal geodatabase in
accordance with the SWFWMD 2006 Topographic Database Design containing: obscured vegetation
polygons; road overpass polygons; road breaklines; soft feature breaklines; water
body polygons; coastal shorelines; hydrographic features breaklines; island polygons;
and 1-foot contours. Final products include FEMA-compliant LIDAR-derived DTM data
and 1-foot contours (for cartographic visualization purposes only) meeting or exceeding
National Map Accuracy Standards for 2-foot contours. This area is not a tract, but
an addition of areas to the Polk District data set. This data set consists of three
areas within Polk County. The approximate bounding coordinates for each area are given
below. Area 3 borders the east and north sides of the Peace River (North) and Judy
Tract data sets. The bounding coordinates for Area 3 are generalized here, but it
is actually a multi-sided polygon with many vertices. Date of Collection: 20050127,
20050130-20050220 Bounding Coordinates of Area 1: Area 2 Area 3 West Bounding Coordinate:
-82.104809 -81.958339 -81.934587 East Bounding Coordinate: -82.033554 -81.918752 -81.380374
North Bounding Coordinate: 28.314262 28.349889 28.397394 South Bounding Coordinate:
28.171749 28.322179 27.625454

DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National
Oceanic and Atmospheric Administration, U.S. Department of Commerce

Originator

Southwest Florida Water Management District (SWFWMD)

Publisher

DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National
Oceanic and Atmospheric Administration, U.S. Department of Commerce

Date(s)

publication: unknown

Data Presentation Form:

Digital image

Dataset Progress Status

Complete

Data Update Frequency:

As needed

Purpose:

The DTM was developed to support the Districts regulatory, land management and acquisition,
planning, engineering, and habitat restoration projects.

Use Limitations

These data depict the elevations at the time of the survey and are only accurate for
that time. Users should be aware that temporal changes may have occurred
since this data set was collected and some parts of this data may no longer represent
actual surface conditions. Users should not use this data for critical
applications without a full awareness of its limitations. Any conclusions drawn
from analysis of this information are not the responsibility of NOAA or any of its
partners. These data are NOT to be used for navigational purposes.

Time Period:

2005-01-27 to 2006-02-27

Spatial Reference System:

urn:ogc:def:crs:EPSG::4269 Ellipsoid in Meters

Spatial Bounding Box Coordinates:

N: 28.357807

S: 27.629413

E: -81.364396

W: -82.081057

Spatial Coverage Map:

Themes

Bathymetry/Topography

LiDAR las digital terrain model

Terrain

Model

Elevation

Surface

Places

US

Florida

Southwest Florida

Polk County

Hampton Tract

Judy Tract

Lake Wales

Peace River (North)

Polk District Remainder

Use Constraints

No constraint information available

Fees

Fee information not available.

Lineage Statement

Lineage statement not available.

Processor

Woolpert, Inc.

DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National
Oceanic and Atmospheric Administration, U.S. Department of Commerce

HAMPTON TRACT, JUDY TRACT, LAKE WALES, PEACE RIVER (NORTH) The LiDAR data was acquired
using a Leica ALS50 from an altitude of 1,000-meters above ground level to provide
an average ground sample distance of 1-meter. The scanner field of view was 44-degrees,
and the scan rate was 33-hertz. First and last return data was collected along with
the signal return intensity. Two redundant airborne GPS bases stations were utilized
during the data acquisition with maximum line-of-sight distance between the base station
and aircraft of 20-km. The LiDAR data was reduced using Grafnav (Waypoint Consulting)
for GPS post-processing, PosProc (Applanix Crop) for IMU processing, ALS50 Post Processor
(LH Systems) to initial LiDAR processing, TerraScan (Terrasolid) for initial point
classification, and proprietary Woolpert developed software for refining the point
classification and QC. The LAS files contain 4 classifications: 1 = unclassified;
2 = ground; 9 = water; and 10 = photogrammetric mass points. The class 1 consists
of all points not on the ground. Class 2 consists of bare earth points. Class 9 consists
of points within water polygons such as swamps and/or wetlands. Class 10 consists
of supplementary mass points that were photogrametrically compiled on points features
such as as peaks or pits, and they were created to maintain the accuracy of the DTM.
Process Date: 20060125 POLK REMAINDER The LiDAR data was acquired using a Leica ALS50
from an average altitude of 3,000-feet above ground level to provide an average ground
sample distance of 3.3-feet. The scanner field of view was 44-degrees, and the scan
rate was 33-hertz. First and last return data collected along with the signal return
intensity. Two redundant airborne GPS bases stations were utilized during the data
acquisition with maximum line-of-sight distance between the base station and aircraft
of 20-km. The LiDAR data was reduced using Grafnav (Waypoint Consulting) for GPS post-processing,
PosProc (Applanix Crop) for IMU processing, ALS50 Post Processor (LH Systems) to initial
LiDAR processing, TerraScan (Terrasolid) for initial point classification, and proprietary
Woolpert developed software for refining the point classification and QC. The LiDAR
data was reviewed in 3D using a digital photogrammetric work station using ADS40 digital
stereo imagery. The LiDAR ground points are adjusted, if needed, to fit the ground.
Breaklines were added to hydrologically enforce the DTM. The edited LiDAR data and
the photogrammetrically compiled breaklines are merged and processed to create the
final DTM files. During the production process, LiDAR data gaps between the flight
lines were observed. These gaps between flight lines were corrected by adding photogrammetrically
compiled mass points. These points are classified as class 10, in the LAS file. In
the areas with the compiled masspoints, it may be noted that the masspoints are not
as dense the areas with complete LiDAR coverage. The masspoints were compiled at a
sufficient density to define the surface to contract specifications. Anomalies were
noted in the 2005 Peace River North and Hampton Tract LiDAR data, during the LiDAR
QA/QC process for the 2007 Remainder Polk County Project. The 2005 LiDAR datasets
for Peace River North (P692) and Hampton Tract (DO19) required additional processing
to ensure correct ground points classification. In areas with gaps in the LiDAR coverage,
photogrammetrically compiled masspoints were added to the surface data. The LAS files
contain 5 classifications: 1 = unclassified; 2 = ground; 9 = water; 10 = photogrammetric
masspoints; and 11 = swamp and/or wetlands. The class 1 consists of all points not
considered to be ground. Class 2 consists of bare earth (ground) points. Class 9 consists
of points within water polygons. Class 11 consists of point within swamps and/or wetlands.
Class 10 consists of supplementary mass points that were photogrametrically compiled
on points features such as peaks or pits, and LiDAR data gaps. These points were created
to maintain the accuracy of the DTM. 3D breaklines were collected at the digital photogrammetric
workstation during the LiDAR data review. These breaklines were delineated to insure
the DTM is hydrologically correct. Hydrologically Enforced Elevation Data is defined
as "Hydro enforced TINS, DEMS, or contours ensure that top surfaces of bridges and
culverts are cut by stream breaklines so that computer models will accurately represent
drainage flow" per FEMA's Appendix A A.4.10. The breaklines were collected for hydrologically
significant features as appropriate to support the development of the generation of
2-foot contours meeting National Map Accuracy Standards. The following breakline features
were classified and separated: Closed Water Body Features, Linear Hydrographic Features,
Coastal Shorelines, Road Features, Soft Features, Obscured Vegetated Areas, Island
Features, Overpasses, and Bridges. Per contract specifications, culverts were not
collected as part of this project. Therefore continuity of hydrographic features may
not be consistent. For a complete description of survey methods, processing methods,
software, system parameters, and accuracy analysis, see the Florida MTS Report of
Specific Purpose Survey, SWFWMD MTS Report of DOI Survey, FY2007 Digital LiDAR (L672)
(dated 4/8/2008)).

The NOAA Coastal Services Center (CSC) received the files in LAS format. The files
contained Lidar elevation measurements. The data was in Florida State Plane Projection
and NAVD88 vertical datum. CSC performed the following processing to the data to make
it available within the LDART Retrieval Tool (LDART): 1. The data were converted from
Florida State Plane West coordinates to geographic coordinates. 2. The data were converted
from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid 03. 3.
The LAS data were sorted by latitude and the headers were updated.

The NOAA National Geophysical Data Center (NGDC) received lidar data files via ftp
transfer from the NOAA Coastal Services Center. The data are
currently being served via NOAA CSC Digital Coast at http://www.csc.noaa.gov/digitalcoast/.
The data can be used to re-populate the system. The data are archived in LAS
or LAZ format. The LAS format is an industry standard for LiDAR data developed by
the American Society of Photogrammetry and Remote Sensing (ASPRS); LAZ is a loseless
compressed version of LAS developed by Martin Isenburg (http://www.laszip.org/). The
data are exclusively in geographic coordinates (either NAD83 or ITRF94). The data
are referenced vertically to the ellipsoid (either GRS80 or ITRF94), allowing for
the ability to apply the most up to date geoid model when transforming to orthometric
heights.